Tests: Add missing instantiation of data

tests/integration/api/discussions/CreateTest.php

@@ -18,6 +18,20 @@ class CreateTest extends TestCase
 {
     use RetrievesAuthorizedUsers;
 
+    /**
+     * @inheritDoc
+     */
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->prepareDatabase([
+            'users' => [
+                $this->normalUser(),
+            ]
+        ]);
+    }
+
     /**
      * @test
      */